12605221 has 2 divisors, whose sum is σ = 12605222. Its totient is φ = 12605220.

The previous prime is 12605207. The next prime is 12605237. The reversal of 12605221 is 12250621.

12605221 = 2510² + 2511².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6305121 + 6300100 = 2511^2 + 2510^2 .

It is an emirp because it is prime and its reverse (12250621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12605221 - 2¹³ = 12597029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12605261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6302610 + 6302611.

It is an arithmetic number, because the mean of its divisors is an integer number (6302611).

Almost surely, 2^12605221 is an apocalyptic number.

12605221 is the 2511-st centered square number.

It is an amenable number.

12605221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12605221 is an equidigital number, since it uses as much as digits as its factorization.

12605221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 12605221 is about 3550.3832187526. The cubic root of 12605221 is about 232.7288131658.

Adding to 12605221 its reverse (12250621), we get a palindrome (24855842).

The spelling of 12605221 in words is "twelve million, six hundred five thousand, two hundred twenty-one".